I was once asked to provide an "official" definition (by 3TonsOfCode, of course) for Presentation Software (the king of the kind being Powerpoint* but let's not limit ourselves), so here it is. Not one, but THREE different Official Definitions. Choose the most appropriate for your own personal drama and use it accordingly.
1. Incompetent Speaker Facilitation Sofware. Speakers - regardless of age, experience, gender or degree of mental stability - can deliver their presentations in front of the most demanding audiences, even when having a lobotomized-cockroach-level IQ. The only thing they usually have to do is read the bullets in a loud voice, until the audience dies from boredom or until they're out of slides. In the latter case, usually NOBODY has any courage left to ask questions, allowing the speaker to gloat like a sunbathing stoned sardine.
2. The Perfect Tool for Designing Applications. Not wireframes, the APPLICATIONS themselves. Yes. However strange it may sound, many people design full-fledged application screens with a presentation app, even complete with animations showcasing how features will actually work. Applications designed this way always appear to be functioning perfectly, exciting the customers and making developers weep, despair, grow green carrots on their armpits and develop suicidal tendencies. OF COURSE things may be slightly different when the application gets actually developed, but who cares about the real world anyway?
3. A Tool for Punishing and Torturing Employees. According to modern trends, telling an employee to "have a presentation for XXXX until tomorrow" (where XXXX is the first most ugly, annoying, difficult and impossible to implement thing that comes to mind) is considered way more humiliating and disgusting than yelling, spitting, throwing valuable office equipment at or even firing the employee. Such an assignment usually leads to hysterical outbreaks, nausea, CD-size skin rashes, purple-colored foreheads (from banging heads on walls, desks and similar horizontal or vertical surfaces) and an urge to redefine one's job description to something that will usually include shovels, bricks, ladders, a lot of sweat and nothing much to think about.
*Powerpoint is a registered trademark of Microsoft Corporation. No Powerpoint users were harmed during writing these definitions. If you are using an alternative to Powerpoint, stop thinking that you're special. You're just doing what everybody else does, just under a different brand name and this doesn't exclude YOU from falling into one of the above definitions. Now go add one more slide, since you've only got 367 for tomorrow's presentation. Poor thing.